Wikipedia has a great page all about the short durometer scale (testing the hardness of a material).It's useful to know what level of 'soft/hard' material you are buying, before you choose for a particular project. Here I'm using Flexfill 98A (Shore hardness 98A or 60D).You can see below that a shore hardeness of 98A indicates a level similar to 'hard wheels of roller skates / skateboards'Flexfill is also available in 92A. This is a little softer, but nothing like a soft stretchy rubber band.Flexfill is ideal for projects like model car racing wheels, textured grips on products, handles etc. It's also great for robot parts that need some flex, but also keep their shape under loads.

Fillamentum Flexfill 98A has a firm, but flexible finish, bends well, but holds shape and form.

Print advice - (Fillamentum 98A) & Just go 30% slower for 92A

What settings did you use? - Flexfill 98A is very forgiving with settings, it's not as easy to use as PLA, but much easier (in a lot of extruder systems) than many softer rubber materials.

You don't always need a heated bed, but it works well with 50 Degrees C PEI surface, thinly covered in gluestick or Magigoo.

First layer speed set to 55% of normal print speed.

Minimum of 2 perimeter (shells) if using a 0.4mm nozzle

222 Degrees C first layer.

233 Degrees C all other layers.

Fans off for first few layers.

Fan at 55% max for printing (normal 25%)

+35% extra Extruder retraction length (from normal PLA settings).

I never use a BRIM, because it's just to tricky to remove, and is not required.

Print speed of 10mm/sec to 60mm/sec depending on your extruder setup. On an i3 MK2 55mm/sec is fine.

Try not to use support, you will find it almost impossible to remove without a very sharp knife.

Why use it? - It's perfect for anything that needs a slightly firmer rubber application. I use it a lot for seals, gaskets and generally any sort of rubber washer or firm grip / texture on a product. Things like gasket seals work well because they are not floppy, but do compress and seal faces together.

Is it strong? - Yes, it's very tough, you will find it very hard to rip, and if you ever need to modify it, only a very sharp knife or heating / deform works. It's hard to snip, cut with scissors and you can;t file or sand it.

Is it easy to use/print - Yes, the biggest issue is going to be stringing, use extra extruder retraction and tune to the speed you indent to print.Do you have to dry it before/after use? - No - it should be good from the sealed pack, but keep it dry.Do i need a 'special' nozzle? - No it's not abrasive at all. All nozzles seem to work well, smaller ones may cause pressure problems with some extruder systems.

Does it smell when printing? - No.

Does it come on a eco friendly spool? - No :( They are generic clear plastic spools, but they do have a recycle logo. I could not make out what material they are made of.

Conclusion for Fillamentum Flexfill 98A- I's a great material to have along side others. You can combine it well with PLA, ABS or PET. You are likely to be using it for some sort of flexing, or model making. It's obviously perfect for many model tyre projects. Check out the OpenRC project for more on that aspect.

Days 1 to 21 of the Advent Christmas Tree. I have no more room here, so it's going to be moved to somewhere in the house for the final few days of Advent.

Day #21 is completed.

Today lets focus the story around the physical uses of different materials in products and applications. It's easy to forget that not everything made is hard plastic or metal. Soft plastic's, rubbers and elastic components make up a lot of products. Especially with things that move or need to form around other devices. Thinking back to my days of being a child at Christmas, if I had a way to print new rubber tyres, skateboard wheels and soft-grips I would have been delighted to receive a roll of Flexfill :)Okay, maybe I just wanted the skateboard, but now I would totally 3D Print some awesome custom wheels for it.

About Me

Richard Horne (RichRap)
is an Electronics Engineer, Product Designer, Salesman, and Problem Solver
working in a wide range of industries and applications, across many platforms
and technologies for the last 20 years.